new 6.5-284 on way need advice for deer hunting

I have a cooper phoenix on the way in 6.5x284. I am buying it from a gentleman who shoots F-class. The gun supposedly shoots best with 139 scenars. "1/4 MOA" I understand that these aren't what you want for hunting. I will be shooting less than 600 yds. Realistically less than 400 99% of the time. What bullet would you guys recommend for 100 to 180 pound whitetail? Also any load information you might find useful would be greatly appreciated.

I would try the 140 grain berger.
i have also used the 142 SMK with good success and the 140 A-Max has worked good for me.
My MV is from 2700-2775 though.
I use H-4350 for all three of mine and H-4831sc is another good powder for the cartridge

I haven't shot them at game yet. They do a heck of a job on the paper though! Any of these that you mentioned leave an exit wound? I have shot 52 gr Watson (benchrest) for the better part of two decades at these deer. My only complaint is there was NEVER an exit wound......Course never had to trail one either....All pretty much dropped in their tracks except one that went 20yds or so, and all shots were less than 200 yds. All of them were neck and head shots. I always insisted on a head or neck due to the fact I knew there would be no exit wound. If the deer around here get off the big clear cuts, they get in to some thick thick stuff. I would like, if possible leave an exit wound so I can boiler room them if need be. I am not so sure I can head shoot them past 200 yds thus my question.

I've killed several with a Nosler 120 Ballistic Tip from a 6.5mm wildcat @2,800fps, but I'd opt against that one at '284 velocities. You might consider a 130gr Scirocco or Barnes TSX. More robustly constructed. Also, something in the neighborhood of a 140gr spitzer from many manufacturers could do the trick for less $$$ than the 'premium' bullets.

I have the same rifle and it killed some deer very cleanly out to 620 yards with both Sierra Matchkings (142) and 140 AMAX. I also used 4350 and also 4831 short cut. One deer went twentyfive yards, the other three were dead in their tracks. The Phoenix is a fine rifle, I get sub 1/2" groups if I am up to shooting well enough. Consistent sub 1" but it will do better if I have my skills tuned up. Put a good scope on it and don't worry about bullet performance, those long bullets will kill deer.